Electric-switch base.



No. 838,171. PATENTED DEC. 11, 1906.

N. W. GRANDALL. ELECTRIC SWITCH BASE.

APPLICATION FILED FEB.27, 1906.

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NATHAN W CRANDALL, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE PERKINS CORPORATION, OF HARTFORD, CONNECTICUT, A CORPORA- TION OF CONNECTICUT.

ELECTREG QWlTCH BASE.

No. sea-171.

Epsciflcation of Letters Patent.

Patented Dec. 11, 1906.

Application filed February 27,1908. Se] lal No. 303.284.

To all whom it may concern:

Be it known that I, NATHAN vilLCRAN- DALL, a citizen of the United States, residin at Hartford, in the county of Hartfordan State of Connecticut, have invented a new and useful Electric-Switch Base, of which the following is a specification.

. This, invention relates to the construction. of the base of a rotary snap electric switch. The bases of these switches are usually formed of porcelain, which is quite brittle. It has heretofore been customary to provide the lockin -plate, which is secured to the front face of the base for the purpose of holding the mechanism while the throwing-spring is made tense and for stopping the mechanism when it is snap ed for opening and closiin the circuits, wit 1 a square hub on its bac face; This hub is set into a square depresthese conditions the locking} 1e recess, which are not big sion or recess in the base in order to prevent the locking-plate from turning. (in account of the unavoidable variations of these recesses,due to the unequal shrinkage of the material during manufacture, it has been necessary to make the square hubs considerably smaller than the recesses they are tooc cu ythat is, when the switches are made in arge quantities it has been necessary to provide a loose fit for the hubs, so that they would always enter the recesses. Under late turns slightly in the recess, so that t our corners only of the square hub on age the walls of the E, and these, affording but small sharp points of contact, radually'chip off and break away the friab e material and in a short time, owing to the constant shock incident to the snapping of the mechanisms, ruin the base and render the switch v; orthless. V A

The object of this invention is to rovide a cheap and strong construction wliich will eliminate the tendency of the locking-plate to break or chip off the walls of the recess in which it is located under the shocks resulting from the snapping of the switch. This object is attaine central depression and depressions extending outwardly therefrom and securing therein a locking-plate which has sto -shoulders on its front face and arms extent ing outwardly from its back face, as more particularly hereinafter described.

by providing a base with 4 shows a section of the base wit 1 the lockingplate. Fig. 5 shows a blank from which the locking-plate is formed. Fig. 6 shows a plan of the lank after it-has been subjected to the formed on its up or surface. Fig. 7 shows the completed loc ing-plate. Fig. 8 shows a section of the completed locking-plate. Fig.

9 shows the locking-plate-holding sleeve, and Fig. 10 shows the nut used for securing the sleeve.

The base 1 is preferabl Y formed circular in outline, with the usuaf perforations for the passage of circuit-wires and, the screws which are used to hold the stationary con- 7 5 tacts in place and the base in position on a wall. Throu h the center of the base isaper foration 2. n the front face of the base about this central perforation is a depression 3, and ex tending outwardly from this depres- 8o sion are depressions 4. These outwardlyextending depressions are preferably deepest at their outer ends.

The locking-plate which is shown is ref-- erably formed from a metallic blank 5. %.his is referably first pressed so as to form the loo big-shoulders 6 on its front side, and then it is stamped to form the outwardly-projecting arms 7. It is preferred that these arms taper from the stop-shoulders and that the 0 outer ends be bent backwardly.

A sleeve 8 is secured to the locking-plate desirably by extending a reduced portion of the sleeve through a perforation in the plate and expanding the front end. This sleeve is 5 thrust into the perforation through the base, and the plate is located with the outwardlyextending arms in the outwardly-extending depressions in the front face of the base.

of the sleeve on the back side of the base for holding the parts from displacement.

The edges of each arm are shown as formed at an angle with each other to insure strength,

1 and while this construction is preferred it is io5 not essential, since the edges may be parallel.

of the base without the ockin -plate. Fig. 60

first operation and the stop-shoulders are 65 Then a nut 9 is Screwed on the threaded end The arms are bent or deflected backwardly at their outer ends for the purpose of giving them a dee er and stronger hold upon the material of which the base is composed, and

this of course also insures higher and stronger Walls for receiving the shock incident to the snapping of the switch. The invention claimed is- 1'. The combination of an electric-switch base formed of insulating material andliaving abutments on itssfront face, and a locking-plate secured to the front face and having stop-shoulders and outwardly-projeeting arms engaging and held by said abutments, substantially as specified.

2. The combination of an electric-switch base formed of insulating n'iaterial having a central perforation and depression with depressions extending outwardly therefrom, and a locking-plate having stopshoulders and outwardlyn'ojecting arms fitting said depressions in the base, substantially as deeper than the central portion, and a locking-plate having stop-shoulders and cutwardlyprojecting and backwardly-bent arms ing abutments on, its front face, and a locking-plate having stop-shoulders on its front "face and outwardly-projeeting and back- Wardlybent tapering arms extending from its back face, said arms fitting and being held by the said abutments, substantialiy as specified.

5. The combination of: an electric-switch base formed of insulating material and having abutments on its ront face, a lockingplate having stop-shoulders and outwardlyprojecting arms mounted on said base and engaging said abutments, a central sleeve extending from the locl ingplate throuh the perforation in the base, and a nut on t e sleeve back of the base for securing the locking-platie in place, substantially as specified.

Nil HAN WI CRANDALL. Witnesses BENZ. C. Pannrss, CnAnLns PERKINS. 

